/Engine/Plugins/Runtime/MeshModelingToolset/Source/MeshModelingTools/Public/EditMeshPolygonsTool.h
(An Inset operation stitches in a smaller version of selected faces inside the existing ones)
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(CallInEditor, Category=FaceEdits, Meta=(DisplayName="Inset", DisplayPriority=2)) void Inset()